Earth mover



D. W. HAWK EARTH MOVE-R March 3, 1964 A2. .Mmw ik -QQW Filed May 14, 1962 United States Patent M 3,122,849 EARTH MOVER Dale W. Hawk, Marion, Iowa, assignor to Allis-Chalmers Manufacturing Company, Milwaukee, Wis. Filed May 14, 1962, Ser. No. 194,518 7 Claims. (Cl. 37l29) This invention relates to earth movers and it is particularly concerned with an earth mover of the type having a bowl supported between front and rear rubber tired units and wherein the front unit is pivotally connected to the bowl on a transverse axis intermediate the wheels of the front and rear units.

In earth mover units of the hereinbefore mentioned type, the push block carried at the rear of the rear wheeled unit is raised and lowered as the bowl is raised and lowered between transporting and digging positions. It is desirable to maintain the height of the push block on the pusher tractor at a predetermined height at which the pusher tractor can exert the greatest pushing effort. In some instances the push block on pusher tractors may be at a fixed height. Although most usually the pushing assistance requirement occurs during digging it may at times be necessary to assist an earth mover by pushing with a pusher tractor when the bowl is in a raised condition. For instance, if the loaded earth mover must go up a relatively steep incline, it may be necessary to assist the earth mover with a separate pusher unit. In prior art earth movers, in which the push block changes height as the bowl is raised and lowered, it is possible of course to provide a push block at a suitable height for pushing when the bowl is in an excavating position, however, in such a design the push block will not be at the most satisfactory pushing height when the bowl is raised to. a transport position. When an engine is installed on a two wheeled rear unit of an earth mover, the engine is most conveniently positioned rearwardly of the axle of the rear unit and thus the rear mounted push block is positioned a substantial distance from the axis of the rear wheels. In such earth movers, the problem of extreme push block height variations is clearly present.

It is an object of this invention to provide an earth mover which takes care of the hereinbefore mentioned difiiculties and requirements in an entirely satisfactory manner.

It is a further object of this invention to provide an earth mover of the hereinbefore mentioned type wherein raising and lowering of the bowl does not adversely affect the elevation of the rear push block.

It is a further object of this invention to provide an earth mover wherein the bowl is pivotally connected to front and rear wheeled units on transverse longitudinally spaced transverse axes and wherein the rear Wheeled unit and the front wheeled unit are interconnected with linkage means automatically maintaining the push block at the rear end of the rear unit at a suitable pushing height.

These and other objects and advantages of this invention will be apparent to those familiar with the art when the following description is read in conjunction with the drawings in which:

FIG. 1 is a top view of an earth mover incorporating the present invention;

FIG. 2 is a side view of the earth mover shown in FIG. 1; and

FIG. 3 is a top view of the lower pivot connection between the bowl and rear wheeled unit.

Referring to the drawings, the invention is incorporated in an earth mover which includes a bowl 12, a front wheeled unit 11 pivotally connected to the bowl 112 on a transverse pivot axis 13 by a pair of pivot pins 14, 16, and a rear wheeled unit 17 pivotally connected to the 3,122,843 Patented Mar. 3, 1964 bowl 12 on a transverse axis 18 by a pair of pivot pins 19, 20.

The wheeled front unit 11 includes a single axle, two wheeled tractor 15 having a pair of rubber tired wheels 21, 22 which are driven through an appropriate power train, not shown, by motive means in the form of an engine 23. The front wheeled unit 11 also includes a draft frame 24 in the form of a yoke having legs 25, 26 the rear ends of which are pivotally connected by pins 14, 16 to the laterally opposite sides 28, 29 of the bowl 12. The front end of the yoke 24 is connected to the two wheeled tractor 15 by an articulated joint including a vertical kingpin member 27. The bowl 12 is raised and lowered by power means in the form of a pair of hydraulic rams 31, 32 pivotally connected at opposite ends to the frame 24 and the front ends of bowl sides 28, 29, respectively. The bowl 12 has a tipout ejector 81 pivoted about axis 32 by a hydraulic ram 83.

The rear wheeled unit 17 is a two wheeled, rubber tired tractor which includes motive means in the form of an engine 36 which drives a pair of coaxial rubber tired wheels 37, 38 through transmission 39 and axle assembly 84. The rear tractor unit 17 is of the single axle type which preferably includes a differential, not shown. The chassis 41 of the rear unit 17 supports engine 36 and presents transversely spaced brackets 42, 45 which are pivotally connected to rearwardly extending brackets 71, 72 of bowl 12 by pins 19, 21 The chassis 41 is integrally formed with the transmission 39 and axle housing 85. A push block 43 is secured to the chassis 41 for movement therewith and extends rearwardly from the driving wheels 37, 38 to a position disposed at the rear of engine 36.

Linkage means 44 in the form of a U-shaped link 46 are provided intermediate the front wheeled unit 11 and the rear wheeled unit 17 to automatically maintain the push block 43 at a suitable pushing height throughout the range of vertical swinging movement of the bowl between raised and lowered positions. The U-shaped link 46 has a pair of forwardly extending legs 73, 74 pivotally conected to legs 25, 26 of yoke 24 by pivot pins 47, 48. The transversely disposed portion 86 of the link 46 includes brackets 49, 50 which are pivotally connected to the chassis 41 of the rear tractor 17 by pins 51, 52 respectively. The linkage means or linkage 44 is effective to maintain the push block 43 at substantially the same elevation even though the bowl is lowered by power means 31, 32 from the transport position illustrated in FIG. 2 by solid lines to an excavating position shown in broken lines 56. Thus the pusher unit such as a crawler tractor 61 having a pushing attachment or fixed height push block 62 on the front end thereof can effectively push the earth mover with the bowl 112 in either its excavating or transporting position.

Without the push block elevation compensating linkage arrangement of this invention, the push block would swing up and down excessively as the bowl is lowered or raised, respectively, thereby making it difiicult or impossible to effectively push the earth mover in both the transport and excavating positions.

The location of the pivot points is such that the transverse axis 63 of pivot pins 47, 48 is spaced vertically upward from transverse axis 13 and longitudinally from the axis 64 of pivot pins 51, 52. Transverse axis 64 is spaced vertically upward from axis 18 and thus it is seen that a novel means is provided between the rear unit, bowl and front unit for automatically maintaining the push block at a suitable pushing height.

The rear unit 17 is detachably connected by pins 19, 29, 51, 52 to the bowl 12 and linkage 44 on transverse axes 18, 64, respectively, such axes being spaced from one 3 another in a vertical direction and from the axis of rear wheels 37, 38.

Although a single embodiment of this invention has been illustrated it is not intended to so limit the invention but rather it is intended to cover such embodiments and modifications as are within the scope of the appended claims.

What is claimed is:

1. In an earth mover of the type having a bowl pivotally connected on a first transverse axis to a front Wheeled unit, the combination comprising: power means for pivoting said bowl and front wheeled unit relative to one another about said first axis, a rear unit having a pair of wheels, means connecting said rear unit to said bowl for relative pivotal movement about a second transverse axis spaced from the axis of said wheels, a push block secured to said rear unit for pivotal movement therewith about said second transverse axis spaced rearwardly of said wheels, and a link pivotally interconnecting said front unit and rear unit on parallel axes, respectively, spaced from each other and from said first and second axes.

'2. The structure set forth in claim 1 and further comprising first motive means for driving the wheels of said front unit and second motive means for driving said wheels of said rear unit.

3. The structure set forth in claim 2 wherein said second motive means includes an engine extending rearwardly from said Wheels of said rear unit and said push block is spaced rearwardly of said engine.

4. In an earth mover of the type having a bowl pivotally connected on a first transverse axis to a front wheeled unit, the combination comprising: power means for pivoting said bowl and front wheeled unit relative to one another about said first axis, a tractor unit having a pair of coaxial driving wheels, means connecting said tractor unit to the rear of said bowl for relative pivotal movement about a second transverse axis spaced from the axis of said wheels, a push block secured to the rear of said tractor unit for pivotal movement therewith about said second transverse axis, and linkage pivotally interconnecting said front unit and tractor unit on parallel axes spaced from each other and from said first and second axis.

5. The structure set forth in claim 4 wherein said linkage includes a longitudinally extending link connected at its forward end to said front unit on a transverse axis spaced in one vertical direction from said first axis and connected at its rearward end to said tractor unit on a transverse axis spaced in said one vertical direction from said second transverse axis.

6. The structure set forth in claim 5 wherein said tractor unit includes an engine for driving said wheels which extends rearwardly of said rear wheels and wherein said push block is at the rear of said engine.

7. An earth mover comprising a bowl, a single axle wheeled unit pivotally connected to the rear of said bowl on a first transverse axis spaced from the axle of said single axle wheeled unit, a push block on the rear of said single axle wheeled unit, a front wheeled unit pivotally connected to said bowl on a second transverse axis spaced forwardly of said first transverse axis, power means for pivoting said bowl relative to said front wheeled unit about said second transverse axis and thereby selectively placing said bowl in excavating and transporting positions, means maintaining the rear of said single axle wheeled unit at a substantially constant height including a link pivotally interconnecting said front unit and said single axle unit.

References Cited in the file of this patent UNITED'STATES PATENTS D. 163,161 Armington et a1. May 8, 1951 2,395,244 Austin ..Feb. 19, 1946 2,399,838 Vaughn May 7, 1946 FOREIGN PATENTS 679,302 Great Britain Sept; 17, 1952 

1. IN AN EARTH MOVER OF THE TYPE HAVING A BOWL PIVOTALLY CONNECTED ON A FIRST TRANSVERSE AXIS TO A FRONT WHEELED UNIT, THE COMBINATION COMPRISING: POWER MEANS FOR PIVOTING SAID BOWL AND FRONT WHEELED UNIT RELATIVE TO ONE ANOTHER ABOUT SAID FIRST AXIS, A REAR UNIT HAVING A PAIR OF WHEELS, MEANS CONNECTING SAID REAR UNIT TO SAID BOWL FOR RELATIVE PIVOTAL MOVEMENT ABOUT A SECOND TRANSVERSE 